I want to implement a menu walker system where only those submenu items get listed which have a specific parent. So let's say I have two level one menu items, A and B. On a page I want to get listed the descendant items of menu A only. I want to use the same menu across the site, so creating two different menus for A and B is not an option.
What I want to know basically, is there a way to get to know the parent item when the walker is going through the menu, so that I skip certain items based on that information.